Physicochemical properties of core/shell structured pyrite FeS2/anatase TiO2 composites and their photocatalytic hydrogen production performances

A new photocatalytic system using anatase TiO₂ loaded onto pyrite FeS₂ (FeS₂/TiO₂) was developed to enhance the production of hydrogen. The FeS₂ (3.0, 5.0, 10.0, and 15.0 wt-%)/TiO₂ particles in SEM photos showed a core/shell structure composed of pyrite FeS₂ with a grape-like morphology of length of ～1.0 μm and anatase TiO₂ of diameter <50 nm. The evolution of H₂ by methanol/water (1:1) photo splitting over FeS₂/TiO₂ in a liquid system was enhanced as compared with that obtained using pure TiO₂ and FeS₂. In particular, 9.8 mmol of H₂ gas was produced in 10 h when 0.5 g of a 10.0 wt-% FeS₂/TiO₂ core/shell composite was used. Hydrogen production was increased by adding KOH electrolyte to 11.2 mmol. On the basis of cyclic voltammetry (CV) and UV–visible spectra results, this photoactivity of the FeS₂/TiO₂ composite was attributed to a shorter band gap than those of pure TiO₂ and FeS₂.